Enhanced strength and ductility of AZ80 Mg alloys by spray forming and ECAP
Enhanced strength and ductility of AZ80 Mg alloys by spray forming and ECAP
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DOI：
10.1016/j.msea.2016.06.031
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发表时间：
2016-07
期刊：
影响因子：
6.4
通讯作者：
Lingling Tang;Yonghao Zhao;R. Islamgaliev;C. Tsao;R. Valiev;E. Lavernia;Yuntian Zhu
中科院分区：
文献类型：
--
作者：
Lingling Tang;Yonghao Zhao;R. Islamgaliev;C. Tsao;R. Valiev;E. Lavernia;Yuntian Zhu
传统AZ 80镁合金的强度和塑性较差的原因是晶界上存在有限的独立滑移系，以及脆性的共晶β-Mg 17 Al 12网络。为了克服这些局限性，采用喷射成形和等通道转角挤压（ECAP）工艺获得了独特的双模态组织：粗晶被平均晶粒尺寸为0.6 µm的超细晶Mg和尺寸为200-300 nm的椭球形β-Mg 17 Al 12颗粒组成的变形网络分离和包围。拉伸测试显示了这种结构的优势：屈服强度为235 MPa，断裂伸长率为14%;这些值明显高于传统的对应物（100 MPa-12%和140 MPa-5%）。讨论和分析了这种特殊组织的强化和变形机制。
The relatively low strength and poor ductility of conventional AZ80 Mg alloys have been attributed to the limited number of independent slip systems, in combination with the formation of fragile eutectic β-Mg17Al12networks at grain boundaries. In an effort to overcome these limitations, spray forming followed by equal channel angular pressing (ECAP) was employed to obtain a unique bi-modal microstructure: coarse grains were separated and surrounded by deformation networks consisting of ultrafine-grained Mg with an average grain size of 0.6 µm and ellipsoidal shaped β-Mg17Al12particles with sizes of 200–300 nm. Tensile tests revealed the advantage of this structure: a yield strength of 235 MPa combined with an elongation to failure of 14%; the values are significantly higher than those of their conventional counterparts (100 MPa-12%, and 140 MPa-5%). The underlying strengthening and deformation mechanisms of this particular microstructure are discussed and analyzed.